Zig-zag sewing machines



y 2, 1964 L. BQNQ 3,132,614

ZIG-ZAG SEWING MACHINES Filed 'Dec. 1. 1960 s Sheets-Sheet 1 gi B0710 4225 1% may 0 A7757 nab May 12, 1964 L. BONO 3,132,614

ZIG-ZAG SEWING MACHINES 1 I IV WW WM WMIII y y 2, 1964 L. B NQ 3,132,614

ZIG-ZAG SEWING MACHINES Filed Dec. 1, 1960 5 Sheets-Sheet 3 UnitedStates Patent 3,132,614 ZIG-ZAG SEWING MACHINES Luigi Bono, Pavia,Italy, assignor to Necchi Societa per Azioni, Pavia, Italy Filed Dec. 1,1960, Ser. No. 72,940 Claims priority, application Italy Feb. 4, 1960 2Claims. (Cl. 112-158) The present invention relates to a sewing machinehaving a transversely movable needle bar and a control mechanism to varythe transverse movements of said needle bar.

In a machine of one type having cams and followers to control thelateral movements of the needle, the cams may be driven with aunidirectional step-by-step motion. The size of the steps may beadjusted so that the number of stitches in a given design are varied tomake the design longer or shorter for a given length of stitch. Since itis not possible to assure that each complete cycle of the sewing designcontrolled by the cam will be made of a definite number of stitches,there will always be small irregularities in the design, but thisdeficiency is more than compensated for by the possibility of varyingthe lengths of theldesigns.

In a machine of another type having cams and followers to controltransverse needle movements, the cams rotate continuously with adefinite transmission ratio to the driving shaft. In these machines,there always are the same number of stitches for each rotation of thecams, so that there can be no variation in lengths of the design withstitches of equal length. But in this case the possibility that theneedle will occupy the identical position with respect to the fabric inmaking the design compensates for the restriction on changing thelengths of the designs.

The object of the present invention. is to provide a machine in whicheither cams designed to rotate stepby-step or cams designed to rotatecontinuously may be mounted to cooperate with the cam followers and bedriven automatically with motion of either form. This mechanism issimple and inexpensive and requires no special preparation by theoperator, except the choice of cams.

The invention will be described by reference to the accompanying drawingwhich shows one embodiment by way of illustration.

FIG. 1 is a view of the sewing machine, partially in section;

FIG. 2 shows details of FIG. 1 on a larger scale;

FIG. 3 is a cross-section through the machine along the line IIIIII ofFIG. 2;

FIG. 4 is a section through the machine along the line IVIV of FIG. 3;

FIGS. 5 and 6 show details of FIG. 3;

FIG. 7 is a view along the line VII--VII of FIG. 2;

FIGS. 8 and 9 are an elevation and a plan view respectively of a groupof cams which can be applied to the machine; p

FIGS. 10 and 11 show in elevation and in plan view, respectively,another group of cams which can be applied to the machine;

FIG. 12 shows sewing designs which can be obtained with a group of camssuch as that illustrated in FIGS. 8 and 9; i

FIG. 13 shows a sewing design which can be obtained with a group ofcams, such as that shown in FIGS. 10 and .11. i

As shown in the drawings, the sewing machine comprises a frame 1 havinga top cover 2 in which a door 3 is located. A driving shaft 4 within theframe 1 operates the usual mechanism to reciprocate the needle bar 5"ice with the needle 5. The shaft 4 also carries gear 6 which engagesgear 7 to rotate vertical shaft 8.

A cam 9 fixed to the lower end of shaft 8 engages the walls 10,11 of achannel in a lever 12 pivoted to oscillate about a pin 13 on anotherlever 14. The lever 14 is pivoted to the frame 1 by pin 16 and carries apin 15 which is maintained in contact with a lever 17, also pivoted onpin 16, by a spring 19. A finger piece on the end of lever 17 extendsthrough slot 18 to the exterior so that the lever 17 may be moved aboutpivot 16 to adjust lever 14 and shift the axis of oscillation of lever12.

The lower side of lever 12 is formed with an arcuate channel betweenwalls, 20, 21, in which slides sector 22 pivoted on an end of lever 23by pin 24. This lever 23 has a roller 25 on its lower side mounted onpin 24 and is pivoted by a pin 26 to arm 27, which is pivoted on theframe by pin 28. The pin 26 also carries a block 29 connected to the rod30 which controls the transverse displacements of support 31 of theneedle bar 5. A channel portion 32 on the end of lever 33 (FIG. 6)receives the roller 25 on lever 23, for shifting the sector 22 in lever12 relative to its axis 14. This lever 33 is pivoted on a pin 35 and maybe adjusted by another lever 36 pivoted on said pin. The lever 36carries an adjustable eccentric abutment 37 engaging lever 33 and has ahandle 38 extending outwardly through slot 39. Adjustment of handle 38to position sector 22in lever 12 relative to axis 13 thereby determinesthe movement of rod 30 and transverse movement of needle 5 resultingfrom oscillation of lever v12, which adjustment of lever 17 to shift thelever 14 and the axis of oscillation of lever 12 will determine thelocation of the median line of movement of the needle.

For automatic sewing, the levers 14 and 33 may be adjusted automaticallyin accordance with a program device operated by the machine, the pin 15on lever 14 and pin 34 on lever 33 being engaged by the automaticmechanism provided for this operation. In the embodiment shown herein, aprogram device comprising a pair of cams such as 77 or 82 is driven fromthe driving shaft 4 through either of two mechanisms to engage sensingmeans such as followers to shift the lever 14 through engagement of pin15 by the slot 41 in lever 43 and the lever 33 through engagement of pin34 by the slot 42 in lever 44.

The lever 43 is fixed to shaft 45 which is rotated by a lever 47. Lever44 is fixed on shaft 46 which is rotated by a lever 48. Shafts 45 and 46have hearings in a plate 49 fastened to the frame 1 by screws 50 inslots 51. Lever 47 carries a stud 52 which is engaged by the edge 54 offollower 57 movable by one of the pair of cams. The lever 48 carries astud 53 which is engaged by the edge 55 of the tail of follower 58movable by the other cam. These followers are pivotally mounted on a pin59, on which is also mounted a third follower 60. This last follower 60may be connected to a stitch-regulating device by rod 61 to vary thefabric feed in a known manner.

One mechanism for rotating the cams comprises a gear 62 on shaft 8driving gear 63, shaft 64, gear 65 and cam engaging gear 66. The gear 66rotates on a sleeve 49 fixed to the plate 49. The other mechanismcomprises a step-by-step intermittent mechanism 69 driving shaft 67. Amechanism of this type is shown in applicants Patent 2,764,895. Themechanism carries an arm 70 which is actuated by the cam 71 fixed to thedriving shaft 4 and is adjustable to vary the length of step throughrotation of cam 72 by means of knob 72. The cam 71 is so positioned onthe driving shaft 4 that the step-by-step movements of shaft 67 occurwhen the needle 5 is in its upper position out of the fabric.

In assembly the two shafts 8 and 64 are journaled in a cylindricalmember 73 seated in frame 1. The member 73 may be rotated in the frameto adjust the clearance between gears 6 and 7, a set screw 74 securingthe member in its adjusted position. Next the plate 49 is fastened inplace and gear 65 is fixed on shaft 64. The slots 51 allow adjustment ofplate 49 for clearance between gears 65 and 66 before tightening screwsSti. The followers 57, 58 and 60 may then be mounted. A lever 75 movableby any appropriate means carries a bent end 76 which can engage the endsof the followers so that they can be moved out of position forpositioning the set of cams on sleeve 49.

One set of cams 77 designed for step-by-step movement has a hub 79formed with a rectangular opening 80 in its outer end to engage therectangular lug 81 on the end of shaft 67 when the hub is mounted onsleeve 49'. The other set of cams has a disk member fixed to the lowerend of its hub carrying a pin 83 which may engage in any one of theholes 84 in the disk portion of gear 66. A washer 68 on sleeve 49provides a bearing between the disk portion and the cams.

In operation, the mechanism disclosed will control both the transversemovements of the needle to vary the length of the steps of transversemovement and the mean position of the needle. The mean position isdetermined by the position of the pivot 13 of lever 12 which is adjusted by angular movement of lever 14, either manually by lever 17 orautomatically by the upper cam of 77 or '78. This cam causes follower 57to move lever 47 and lever 43, which shifts lever 14 through pin 15. Thelength of the lateral movements of the needle are dependent onpositioning lever 33 to locate the sector 22 so that oscillation oflever 12 moves the needle according to the distance of sector 22 frompin 13. The lower cam also may adjust lever 33 by shifting follower 58which rotates lever 48 and lever 4a to shift lever 33 through pin 34.

When the operator selects a design to be sewn, one of the cams such as77 is positioned on the sleeve 49' to be driven step-by-step by themechanisms 69. The knob 72 may then be adjusted to control the size ofthe steps without varying the length of the stitch. Differentadjustments of the steps for equal size stitches form designs as shownin FIG. 12. The other cam 78 may be mounted with its hub 82 on sleeve49' and pin 33 engaged in a hole 84 in the disk portion of gear 66 sothat the cams will be driven continuously. By choice of cams andsimultaneous control of feed of the fabric, various designs may beobtained such as shown in FIG. 13.

I claim:

1. A sewing machine comprising a drive mechanism, a needle, means drivenby said drive mechanism for reciprocating said needle, other meansdriven by said mechanism for effecting lateral movement of said needle,and control means connected to said other means for controlling saidother means, said control means including cam followers adapted toengage a plurality of replaceable cam units, two separate cam unit drivemembers, means driven by said drive mechanism for continuously rotatingone of said cam unit drive members and simultaneously, intermittentlystep-by-step rotating the other of said cam unit drive members, said camunit drive members being relatively movable and in the form of coaxialrotating members, one of said rotating members having a disk and theother a shaft projecting axially through said disk, separate anddifferent cam engaging means on said disk and said shaft, saidcontinuously rotating cam unit drive member engaging means being adaptedto engage only a replaceable cam unit having complementary engagingmeans, said intermittently stepby-step rotating cam unit driving memberengaging means being adapted to engage only a replaceable cam unithaving complementary engaging means.

2. The sewing machine of claim 1 wherein said cam units are in the formof stacked sets of cams.

Fischer Jan. 3, 1961 Casas-Robert et al. Apr. 11, 1961

1. A SEWING MACHINE COMPRISING A DRIVE MECHANISM, A NEEDLE, MEANS DRIVENBY SAID DRIVE MECHANISM FOR RECIPROCATING SAID NEEDLE, OTHER MEANSDRIVEN BY SAID MECHANISM FOR EFFECTING LATERAL MOVEMENT OF SAID NEEDLE,AND CONTROL MEANS CONNECTED TO SAID OTHER MEANS FOR CONTROLLING SAIDOTHER MEANS, SAID CONTROL MEANS INCLUDING CAM FOLLOWERS ADAPTED TOENGAGE A PLURALITY OF REPLACEABLE CAM UNITS, TWO SEPARATE CAM UNIT DRIVEMEMBERS, MEANS DRIVEN BY SAID DRIVE MECHANISM FOR CONTINUOUSLY ROTATINGONE OF SAID CAM UNIT DRIVE MEMBERS AND SIMULTANEOUSLY, INTERMITTENTLYSTEP-BY-STEP ROTATING THE OTHER OF SAID CAM UNIT DRIVE MEMBERS, SAID CAMUNIT DRIVE MEMBERS BEING RELATIVELY MOVABLE AND IN THE FORM OF COAXIALROTATING MEMBERS, ONE OF SAID ROTATING MEMBERS HAVING A DISK AND THEOTHER A SHAFT PROJECTING AXIALLY THROUGH SAID DISK, SEPARATE ANDDIFFERENT CAM ENGAGING MEANS ON SAID DISK AND SAID SHAFT, SAIDCONTINUOUSLY ROTATING CAM UNIT DRIVE MEMBER ENGAGING MEANS BEING ADAPTEDTO ENGAGE ONLY A REPLACEABLE CAM UNIT HAVING COMPLEMENTARY ENGAGINGMEANS, SAID INTERMITTENTLY STEPBY-STEP ROTATING CAM UNIT DRIVING MEMBERENGAGING MEANS BEING ADAPTED TO ENGAGE ONLY A REPLACEABLE CAM UNITHAVING COMPLEMENTARY ENGAGING MEANS.